Reviews by patients who have Tooth Pain and take Zinc either as part of daily diet or as method of treatment. Positive and negative experiences from patients with Tooth Pain that take Zinc
1 Red or black colored stool may be a sign of bleeding in the GI tract (from the esophagus, stomach, small intestine or colon) and should not be ignored.  When stool color changes, what tests need to be done depend upon depends upon what cause is suspected for the stool color change.
Medicine and Healthcare. Black stools can be due to iron supplements or excess iron in the diet. The most serious cause of black stools is bleeding in the GI tract, due to ulcers or some other cause. If the stool is black due to blood, it usually has a tarry feel. If there is just a black color, most likely it is not blood.